Merge \\"Delete the NDK docs from Git. They\\'re now in Piper, as per: https://critique.corp.google.com/#review/126357681\\" into nyc-dev am: 5460fef952
am: 6a8fa04b6f

Change-Id: Id3d402fabe9e2dc73dcd5ded226f3223fc4f3d3c